低孔渗泥质砂岩储层并联导电模型分析及改进

Analysis and improvement on the conductivity model of low porosity and permeability shaly sand reservoirs

针对泥质砂岩储层最常用的并联导电模型W-S和双水模型,提出视地层因数与真实地层因数的比值F_a/F,用来表示泥质砂岩偏离阿尔奇砂岩的程度,并根据F_a/F的变化规律,分析Q_v对泥质砂岩储层导电模型的影响.结合实验室条件下Nacl溶液的电导率范围,指出W-S模型在泥质较重的地层中无法得到真实的地层因数.改进双水模型的计算方法,避开Q_v测量的不准确性带来的误差,而通过改变饱和溶液的电导率来得到岩样真实的地层因数.实验证明,改进双水模型的模拟结果比W-S模型与泥质砂岩的岩电实验数据更吻合.

Waxman-Smith model and Dual-water model are the most commonly used conductivity models in the shaly sand. The ratio of apparent formation factor and the real formation factor is proposed to indicate the degree of deviation from Archie sandstone.And the influence of Qvfor the conductivity models of shaly sand is analyzed according to the change law of Fa/ F. Combining with the conductivity of Nacl solution under the condition of laboratory,we are unable to get the real formation factor of heavy shaly sand in the W-S model. The thesis avoids the error brought from the measurement of Qvby improving calculation method for the Dualwater model,and gets the real formation factor of the core by changing the conductivity of saturated solution. Experiments show that the simulation result of the improved dual water model is more accord with experiment data of shaly sand cores than W-S model.